The 1998 field season witnessed a lot of activity at Cahokia. There were four projects at the site, each quite different. The first three were funded, in part, by the Cahokia Mounds Museum Society.

The Northwestern University (NU) field school, under the direction of Dr. Mary Beth Trubitt, opened several test units this summer, as part of a multi-year project to pursue the route of the Stockade/Palisade wall around the western and northern portions of the site.

They began by reopening a unit that Washington University (WU) had dug in 1971 behind Fox Mound (of the Twin Mounds). They relocated the stockade trench that WU had identified and enlarged the excavation to expose more of it, as well as another large basin-shaped feature that seems to be superimposed by both these features.

Several other units were opened to the west of Round Top Mound and the one that is situated on a slight north-south ridge revealed linear features that are believed to be one of the Stockade bastion trenches. In the other units they revealed part of a wall trench structure and basin and several other features, including a possible edge of a borrow pit. Several Society members participated as volunteers in this project.

The University of Wisconsin-Milwaukee, under Dr. Melvin L. Fowler, expanded an excavation trench in Mound 96 to further expose a "sand-filled basin" Feature there as well as a couple others nearby that were partially exposed in 1997. Rob Watson was the field director and he eventually will be developing this research into a Ph.D. dissertation.

The basin in Mound 96 is somewhat enigmatic and at one point was thought to have been a possible added terrace but, at the end of the dig, the concept of a large basin feature was gaining strength again as more of the area was opened up to the east. In this area, it became clearer that this was a large feature and another sand-filled feature was appearing to the east, with two wall trenches between, and possibly connecting them.

In one of the other units to the north, what was thought last year to be another sand-filled basin turned out to be part of large wall-trench structure that is divided internally into two rooms. In another unit a sand-filled basin was superimposed by a wall-trench structure that is divided internally into two rooms. In another unit a sand-filled basin was superimposed by a wall-trench structure. In the northernmost unit, amidst a tangle of tree roots, a small pit feature was located and in the fill was a ceramic owl effigy pendant and a fair amount of ceramic sherds.